Abstract
Abstract
OBJECTIVES
Bone health deterioration is a major public health issue. General guidelines for the limitation of bone loss prescribe a healthy lifestyle and a minimum level of physical activity. However, there is no specific recommendation regarding targeted activities that can effectively maintain lumbar spine bone health. To provide a better understanding of such influencing activities, a new predictive modelling framework was developed to study bone remodelling under various loading conditions.
METHODS
The approach is based on a full-body subject-specific musculoskeletal model [1] combined with structural finite element models of the lumbar vertebrae. Using activities recorded with the subject, musculoskeletal simulations provide physiological loading conditions to the finite element models which simulate bone remodelling using a strain-driven optimisation algorithm [2]. With a combination of daily living activities representative of a healthy lifestyle including locomotion activities (walking, stair ascent and descent, sitting down and standing up) and spine-focused activities involving twisting and reaching, this modelling framework generates a healthy bone architecture in the lumbar vertebrae. The influence of spine-focused tasks was studied by adapting healthy vertebrae to an altered loading scenario where only locomotion activities were performed.
RESULTS
The spine-focused activities were responsible for 57% of the overall bone mechanical stimulus of the five lumbar vertebrae. Cortical bone maintenance was more influenced by these activities in the superior vertebrae than in the inferior ones, with a stimulus degradation of 74% in L1 against 24% in L5 when adapted to the altered loading scenario. Trabecular bone stimulus degradation varied between 53% and 68%.
CONCLUSION
The study suggests that locomotion activities are insufficient to maintain lumbar spine bone health. When appropriate, larger spine movements should be recommended as part of the minimum daily physical activities.
Declaration of Interest
(b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
